1. Field of the Invention
The invention pertains to a rider roller assembly for exerting a load force to at least one wound roll of a web-like material, such as at least one roll of paper, during the winding in a winder comprising at least one supporting or carrier drum, supporting or carrying the wound roll being rotary-driven on its axis of rotation, with the features according to the preamble of claim 1.
2. Description of the Prior Art
A generic rider roller assembly comprises
a support beam for translational movement, which is substantially vertically movable relative to the wound roll depending on the diameter thereof, PA1 driving means for moving the beam, PA1 a rider roller including a plurality of individual rider roll wheels, which are rotatably mounted to the beam and are capable to engage the wound roll along a contact line (nip line), PA1 supporting arms, which are articulately linked to the beam for holding and independently pivoting the rider roll wheels on a swiveling axis relative to the beam, PA1 pressing means for hydraulically pressing the rider roll wheels against the at least one wound roll, and PA1 means for pneumatically balancing out or lifting the rider roll wheels from the at least one wound roll counter-balancing the pressing means, and optionally, counter-balancing the weight of the rider roll wheels.
Generic rider roller assemblies are known from U.S. Pat. No. 5,320,299. By virtue of its citation, the disclosure of this document is fully incorporated in the disclosure of the present description.
In this known rider roller assembly, the pivoting of the individual rider roll wheels on its associated supporting arms each is effected by means of a piston rod, which is loaded at each end by piston/cylinder units, the middle section of which has a joint for pivotable link with the associated supporting arm. It has been shown that these known rider roller assemblies already represent a significant advance in improvement of the windings of the wound roll. However, the piston/cylinder units acting on the same piston rod at both ends must be exceptionally precisely aligned. Further more, the corresponding supporting arm transmits a transverse force to the piston rod due to its pivoting on its swiveling axis.
AT 357,861 describes a rider roller assembly having a plurality of rider roll wheels each rigidly fixed to one end of a piston rod. The rider roll wheels are moved in the axial direction of the piston rod by means of a hydraulically actuated elements, serving also as vibration dampers.
DE 21 47 673 discloses a roller assembly having a plurality of rider roll wheels being pivotably mounted by means of lever elements to a beam, wherein pressure chambers fluidly connected with each other are arranged inside the beam. To cause pivoting of the roll wheels, the pressure chamber is linked via membranes to the lever elements.